Long-term ambulatory peritoneal insulin infusion of brittle diabetes with portable pumps: comparison with intravenous and subcutaneous routes.

This work compares different routes of insulin infusion via portable pumps with chronically implanted catheters and evaluates the long-term feasibility of the technique. Six severely unstable (i.e., uncontrolled by optimized intensive insulin therapy) diabetic individuals (age range: 35 +/- 4 yr; duration: 11 +/- 2 yr) were selected. Promedos pumps (Siemens A. G., Erlangen, West Germany) were exclusively used because of their portability and long-life insulin reservoir (1-mo duration with U40 acidic Hoechst insulin). Each patient underwent three randomized 1-mo periods of insulin infusion: subcutaneous (s.c.), intravenous (i.v.), and intraperitoneal (i.p.) before the catheter was left indefinitely in one of these sites. Diabetic control was improved and insulin doses reduced whatever the route of infusion, although the s.c. route gave slightly higher values. These results did not deteriorate with time: mean blood glucose was 126 +/- 3 mg/dl and HbA1 was 8.3 +/- 0.6% after 10-18 mo of constant infusion versus 237 +/- 35 mg/dl and 10.0 +/- 0.8%, respectively, under conventional therapy. From a practical point of view, the i.p. route seems preferable since all s.c. catheters provoked local reactions after less than 1 mo and the two chronic i.v. catheters obstructed after 8 and 9 mo. All other incidents were minor and curable without removal of the catheters. All patients argued improvement of both diabetes and quality of life and no one has resigned so far. Thus, the i.p. infusion technique seems beneficial to unstable diabetic individuals and adaptable to long-term therapy, although intensive education and careful follow-up are necessary.